I have this router that's working well. I got it because at the time,
I needed a router that would work with an AT&T 3G Sierra Wireless USB
connect modem.... and it worked fine for several years. What I'd like
to know, is will it work with a similar, but 4G Sierra modem? I
checked the manual, and it states:

I know EVDO is old technology.... Is HSPA equivalent to what I call
3G, or does it include 4G.... that is, will this router work with a 4G
input signal using a 4G sierra modem?